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Database schema modeling runs locally in your browser. Table structures, column names, and schemas are never uploaded without your consent.
ER Diagram Maker — Entity-Relationship Schema Designer
Interactive entity-relationship diagram generator for SQL databases and data modeling.
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Free, no signup
Accurate data modeling is essential before writing SQL migrations or ORM models. Entity-Relationship (ER) diagrams communicate table structures, primary keys, foreign key constraints, and relational cardinalities.
Our ER Diagram Maker provides interactive table entity modeling with primary and foreign key indicators, column data types, and 1:1, 1:N, and M:N relationship connectors.
How to use this tool
1Click "New Database Table" to add a schema entity to the canvas.
2Add column definitions with data types (e.g. INT, VARCHAR, UUID) and mark Primary Key (PK) or Foreign Key (FK) flags.
3Define relationships between parent and child tables with cardinality connectors (one-to-many, many-to-many).
4Export to vector SVG, high-res PNG, or standard Mermaid erDiagram code.
Frequently asked questions
Can I export ER diagrams to Mermaid erDiagram syntax?
Yes. Diagram Studio generates standard Mermaid erDiagram code ready to embed in markdown docs.
Does the tool support primary and foreign key indicators?
Yes. Columns can be flagged with PK and FK indicators, with color-coded badges on table headers.
Is there a limit on how many tables I can add?
No. You can model schemas of any size with smooth infinite canvas panning and zooming.